Synthesis and Characterization of Processable Polyimide Titania Nanohybrids

A new aromatic diamine monomer {4-amino [4-(diphenylamino) phenyl] anilino} phenyl amine (DPA -4) were synthesized in high yield and purity. {4-amino [4-(diphenylamino) phenyl] anilino} phenyl amine (DPA -4) monomer were reacted with Tetra carboxylic dianhydride (BT) leading to the formation of polyamic acid, followed by the preparation of polyimide/Titania hybrid films through non-hydrolytic sol-gel method. The synthesized polyimide were considered as blank & compared with the nano-hybrids derived from polyimides/Titania blends of different TiO2 content. Synthesized polyimide showed excellent solubility in aprotic solvents like DMF, DMSO, NMP, and DMAC proving best processibility in various applications. Polyimide exhibited excellent thermal stability and its glass transition temperature was 450 degrees C & 5% weight loss is in the range of 500 degrees C similar to 600 degrees C. The thermal stability of Polyimide/Titania composites decreased slightly with increase of TiO2 content. Result show decrease in thermal stability of nano-hybrids caused by the decomposition of catalytic activity of Titania & incomplete imidizations of polyamic acid. The absorption band of PI-O-Ti bonds in FTIR spectra of hybrids films revealed the formation of hybrid inorganic network between polyimide and TiO2.Scanning electron microscopy results indicated that the nanometer-scaled inorganic domains were homogeneously dispersed in polyimides matrix due to the introduction of TiO2. The studies on the optical properties of hybrids films indicated the red-shift to the absorption band increased with increasing TiO2 content, while all the hybrids films maintained their transparencies. This kind of hybrid materials has potential commercial application in the field of opto-electronics appliances.